My first attempt at hypermiling = FAIL

Recently (May 2, 2013), I was practicing my high speed Driving With Load (DWL) hypermiling skills on an extended road trip (pre-warmed up 2010 Prius III, 61 mpg, over 621.5 miles using 10.14 gallons of E10 87 oct regular gas from Germantown, Maryland to Grand Rapids, Michigan). In California, under ideal weather and road conditions, Elite Hypermiler Wayne Gerdes reported some very good fuel efficiency results with a pre-warmed up Prius c using DWL (+80 mpg) so my focus has been for some time to refine my DWL skills. The posted speed limit on my interstate route was between 55 to 70 mph with 99% highway miles - my average speed over 50 mph. Some segments of my trip had a minimum posted speed limit of 55 mph. In some road construction segments the PSL was from 55 mph to 45 mph. My interstate route was from I-270 to I-70 to I-76 (Pennsylvania Turnpike) to I-80 (Ohio turnpike) to Michigan I-70N/I-475W/I-23N/I-96W. The DWL technique I was trying to learn: At the top of the hill, on the down hill speed up to a top speed ( Gerdes was using 65 mph, but I was using 70 mph), on the uphill pull back the throttle so the Scangauge xgauge LOD=75 (75 is suppose to be a magic number that prevents the ICE from using oversaturated fuel mix, but I was using a LOD as high as 90 because I was working at a higher elevation which required a higher fuel mix just to keep up the the min PSL of 55mph at higher elevations ). In DWL, on an extended downhill slope ( + quarter(.25) mile downhill segments) there is a bit of play as to where one accelerates on the downhill to gain the speed and how much speed does one add to go uphill again - figuring this out is a skill. However, as Sagebrush mentioned, in many cases, a slight downhill segment of the road does not have enough gravitational potential energy to sustain a high speed coast(low/no electric motor power, no/low ICE power), so as the Prius is going downhill I pulsed/accelerated the Prius to the PSL (e.g. PSL=70mph) and then pull back the throttle so LOD=80 and then I allowed the Prius to slowly decelerate to the minimum PSL (e.g. 55 mph) before pulsing again. In upper elevations, the Prius' ice start to lose quite a bit of horsepower - especially when going up long extended uphill segments and trying to maintain the minimum PSL of 55 mph along the PA turnpike - where I found myself hitting a LOD=85-88. In order to have more control over my speed, try to time my trip when the turnpike would have the least amount of traffic - non rush hours during Wednesday-Thursday and Saturday-Sunday. I got off of the Ohio turnpike several times to avoid traffic jams. I caught the bug while I was in Grand Rapids and it got progressively worst on the returning trip - which limited my ability to hypermile -- hence my MPGs dropped significantly on the way back.

 

I'm looking to get something like a scan gauge, what made you choose this one? Where do you plug this in and where do you see the read-out? I know nothing about these devices, if you can't already tell

 

That is a wireless Bluetooth dongle. You have to use your smartphone and an app like Torque to access the vehicle. So the readout is on your phone.

 

Joe-G,
Nice improvement, from low 50s to 60s MPG. Well done!

I'd like to hear what changes you have made to your driving to gain that improvement.